BY M. J. THOULET.

Translated for The Chautauquan from the RÉvue Scientifique.

The definition given to-day to mineralogy places it among the exact sciences. Long continued study has shown that it possesses all the inflexibility of chemistry, of physics, of mathematics. The work of one making a specialty of this subject is similar to that of a millwright who collects the different pieces, forged and cast and prepared in various ways by other workmen, and arranges them all in their proper relations to one another, joins them, and forms the mill with all its complication of machinery in good order, ready to run without friction, without jar. The mineralogist gathers up the facts and theories wrought out by workers in other fields of science, studies their variations, their agreements and connections, demonstrates their presence and their union in inorganic bodies, and sums up and announces all the results of his labor in the form of laws which shall be exact rules for events past, present, and future; for a science incapable of foreseeing and foretelling is not a true science. Mineralogy is not chemistry, nor physics nor mathematics, any more than the millwright is the smith or the smelter. It is a distinct science pursuing a particular aim, and which, although borrowing from other sciences certain of their results, nevertheless possesses its own individuality. It might be said to be a direct application of these three sciences, together with geology, to the study of the life of minerals.

I have just used a very significant expression: The life of minerals. Others have used it before me. “Not only do stones live, but they suffer from sickness, from old age, and death,” wrote Cardan in the sixteenth century. And he was right. Eternal matter performs an eternal cycle; the incessant variations which it experiences; the movement which is never arrested, which from modification to modification, from transformation to transformation draws it along without a single moment of rest; the continual births and deaths and resurrections are life. Every man, every animal, every plant, and every stone obey without any power to resist, and they are all borne along without relaxation or repose toward a vortex whose beginning and ending are concealed within the shadows of eternity. There is no difference between the mineral and vegetable, or animal. Inorganic life is identical with organic life, varying only in degree.

From the moment which we call birth, that is to say at the commencement of one of these periods of transformation, our eyes see, hour by hour, moment by moment, the living being develop. The atoms entering into its construction seek like atoms to which they ally themselves, and molecules combine with other molecules. What matters it about the form of being? Simple or complicated, the law is the same, and it is obeyed. The individual appears with its own chemical constitution, its own form and look, its own variations, all decided under its predetermined conditions. Among these conditions a single one is variable, but the equilibrium is constantly preserved; the individual changes from time to time in its own appointed way, but it never ceases to exist.

In the same manner as organic life bears the impress of its surroundings, so do minerals submit themselves to external influences. The one perhaps is more frail, more delicate, less able to resist, more susceptible to impressions; the natural forces of the other, more powerful because they are simpler, yield less readily to circumstances. Both alike are forced to take their part in the great concert of forces in which they fare only infinitely feeble notes; both alike are influenced by the majestic assembly of powers which act upon them, and upon which they, in turn, also act, conformably to one of the first laws of matter, that of equality between action and reaction.

Let us take any mineral whatever and subject it to a constantly increasing temperature. We notice first that it undergoes a change of form. Cease the application of heat and it will gradually resume its former shape. Let us heat it again, and more intensely. All the properties of the matter which constitutes it become changed, some quickly, some slowly, and it is incapable now of taking back its first appearance. Its crystalline form is different, and its mechanical elasticity, its hardness, and its electric properties; even its color is changed. We will still increase the heat. The molecules disperse, following certain directions, and, following others, gather themselves together. Suddenly a limit, varying according to the chemical composition, the crystalline type, or the pressure, is broken; the solid, beginning to melt, becomes a liquid. Heat it still higher and we shall see new phenomena appearing, volatilization and dissolution. Another limit is passed and the atom, becoming isolated, is free henceforward from the laws of chemistry, and must now obey laws yet unknown, the task of discovering and formulating which is awaiting some worker in the realms of physics or mechanics.

The dissolution of a mineral, is it not death? Every abrupt limit of all the powers of a body is death, and all death precedes a resurrection.

As a child, which at the same moment when it opens its eyes upon the light and utters its first cry, begins already to die, so with the mineral scarcely formed, death commences. Feldspar, which constitutes in great part the soil pressed by our feet, under the influence of air and of water, of drought by day and dews by night, of the heat of summer and the cold of winter, of all agents mechanical, chemical and physical acting upon it, is reduced to its elements by a series of almost insensible transformations. Its fragments are broken to still finer bits, and when they have become dust disintegration still goes on, and gradually the silicon, the aluminum, the iron, the lime, the magnesium, and the potassium which composed them form clay. The iron oxydizes, the silicon separates itself, is dissolved by rain and carried off by the streams. Each element then enters into a new combination; sometimes it again becomes part of a stone; sometimes it helps to form the structure of a plant; sometimes that of a man. Where can birth, signifying the beginning of all existence, be placed, or where shall we find any real death? I perceive only periods of life.

Of old, naturalists made more frequent and much stronger affirmations than they do to-day. Confidence in self is the property of youth; maturity learns to doubt, which is the beginning of wisdom, provided that it does not remain content, but rather compels man to seek with increased ardor the truth which seems to fly from him. The ancients placed between the animal and the vegetable limits which in reality did not exist. Up to the present time limits of the same nature have been set between organic and inorganic life. But in proportion as we examine minerals we shall see the differences disappear and the resemblances increase. Man is born of parents; the whole animal and vegetable worlds are perpetuated in obedience to the laws of reproduction, each after his own kind. It was this absolute identity between parent and offspring that separated distinctly the other kingdoms from the mineral; but recently a scientist has discovered that the same fixed law is established in this department of life also. M. Gernez prepared a solution consisting of octahedral borax in five equivalents of water, and rhomboidal borax in ten equivalents of water. The two bodies, excepting their proportion of water, had the same chemical composition. The liquid, treated with suitable precaution, remained perfectly limpid, and he could place in it fragments of all imaginable substances, without causing it to give rise to any remarkable phenomena. But when even an infinitely small crystal of octahedral borax was dropped into it, the temperature rose, and in a few minutes all the octahedral borax contained in the solution took the crystalline form. Meanwhile, the rhomboidal borax was held in solution, and in order to crystallize it in its turn, there was needed only the contact of a rhomboidal crystal.

The mineral was evidently born of a parent; it was identical with this parent; its symmetry was the same under the same circumstances. Similar results from numerous experiments with other substances were obtained.

… Under the influence of agents whose masters we are, molecules group themselves, following fixed laws, and arrange themselves in their relative positions. Just as soldiers off drill, and scattered throughout the camp, when the order of the commander is given, obey and fall into line, so do molecules obey the forces in command over them.

Stranger still, this crystal perfectly formed, seems sometimes to have a conception of an ideal of beauty, a perfect symmetry, the ellipsoid of the cubic system, which is a sphere; it seeks it, tries to reach it, and if it can not be attained, it falls to acting a part. It disguises itself, just as is sometimes done among men, and strives to appear the being it is not. The crystal, no more than the man, will ever assume a place in a lower rank; each seeks to appear better than he is. To attain its object the crystal will unite itself with the other crystals of the same kind; then these will gather into groups. As they can not modify their own angles they will crowd one against another. Let it cost what it may, if it is a possible thing they will have their imperfections removed, and will improve their individual appearance, and if any measure of success is attained, the little crystals will enjoy in silence their usurped glory.

If science, with the apparent rigidity of her measures, weights and figures holds for the scholar oftentimes disagreeable surprises, she sometimes cheers him by rewards full of a strange grandeur. Azote, or nitrogen in its free state, constitutes more than three fourths of the volume of the atmosphere, and is in its appearance the type of inertia. Its presence seems to have no other rÔle than to reduce the over-exciting action of the oxygen upon our organs of respiration. In order to cause it to enter into combination with other substances, it is necessary to have recourse to the most energetic forces. Among these in nature only one, electricity, lightning, is able to accomplish this result. But the union once effected, the gas is capable of undergoing a thousand variations. As passive as it was while free, so active does it become after entering into any combination. As it is found in the constitution of all animal and vegetable life, we find that without the storm-cloud no organic life could exist. The origin of all creatures is to be found in a clap of thunder.

Such examples as these show that imagination as well as science derives great profit from the intimate study of the phenomena presented by minerals. One commences their study by measuring, by weighing, by carefully analyzing; one gathers now and then slowly a little knowledge; then suddenly this apparently barren field disappears to give place to large horizons, to vast generalizations of majestic simplicity, resting upon the solid foundation of experimentation. Let us not underestimate the rÔle of the imagination in scientific researches. It gives to the scholar persistence in his daily toil; it is his hope at the moment he begins an undertaking, his guide during the work, and his recompense when he has finished. What a charm in the frequent discoveries of analogies between the highest orders of beings and those which occupy the lowest rounds in the ladder of perfection!

Similarity is to be observed also in the growth of individuals in the different kingdoms. One sees at first crystal skeletons, then gradually the crystals developing into perfection. Neither the chemist with all his delicate tests, nor the physician armed with his accurate instruments can decipher the feeblest trace of heterogeneity; the child grown has become a man; the mineral fully developed has reached also its age of virility.

Minerals may be hindered in their development, may become irregular, imperfect, deformed; upon certain of their angles new facets may appear, in other parts facets may slowly become obliterated. As soon as the obstacle causing the trouble is removed the wounds will heal over, perhaps leaving their scars, and the crystals will pursue their normal course. Sometimes an accidental circumstance, as that of too ardent a sun, or a season too wet, will cause a fissure, and a malady commences. Oxydation or hydration is produced, and the mineral begins to disintegrate; finally, as a result of the accident, the last particles are lost to sight. We think it has been destroyed. But it is dead; it has died just as a man dies. Its elements are just as imperishable as are those of man’s body, which, when it is laid away in the grave are not annihilated, but, as they are resolved, enter again into new forms in the great torrent of life. Their atoms are immutable, what they have been, they are, and will be to all eternity; eternally young, eternally the same, moving without rest, unmindful of time or of combinations. The ancient symbol of the serpent with his tail in his mouth well represents the cycle of life. Periods succeed periods.

The day ends in twilight and the night is followed by a new dawn. All limits are effaced. The stone, the flower, the animal intermingle their natures. With this thought in mind all life seems like a great net-work, whose meshes are interlaced in countless ways, before which the seeker after truth stands with ardent soul. But at the moment he thinks to grasp the solution of the absorbing problem, he is only made more deeply aware of his own weakness. And looking forward over the great expanse stretching out before him to infinity, he experiences only one sentiment, that of admiration; and his desire ever increases to learn still, and to learn always.